The transition metal catalyzed carbo-carbon and carbon-hetero atom bond formations via the activation of SP2/SP3 C—H bonds has been recognized as a powerful alternative to the classical cross-coupling reactions involving the pre-functionalized coupling partners. The direct and directed C—H addition of heterocycles to olefins has been extensively investigated by employing various transition metal complexes. In general, these reactions preferentially provide the linear adducts. In rare cases, such as styrene when employed as an olefin counterpart, the branched selective hydroarylation has been documented. Coming to the olefins conjugated with an electron withdrawing group such as acrylates, depending upon the conditions employed, the directed cross dehydrative couplings lead either to alkylation or alkenylation or both in a linear fashion. Surprisingly, with acrylates and related derivatives, there were no reports where the formation of substantial amounts of branched adducts had been noticed.
WO 2007011835 discloses benzofuranyl compounds and hydrates, solvates, salts thereof obtained from pyranobenzofuran.
EP0623607B1 discloses benzofuranyl-and-thiophenyl-alkanecarboxyclic acid derivatives and process for preparation thereof.

The benzofuran is an important structural unit present in a variety of natural products and received significant recent interest in the development of new pharmaceuticals. The 2,3-disubstituted benzofurans deserves a special mention as they served as building blocks for a number of natural products synthesis and possess unique biological activities. For example, 3-(2-aroylbenzofuran-3-yl)propanoates and their regiomeric counterparts—the 2-(3-aroylbenzofuran-2-yl)propanoates have been identified as novel anti-inflammatory agents. The former compounds are known to inhibit the type IV phosphodiesterase which results in the elevation of cellular cAMP that regulate the production of superoxide by polymorphonuclear leukocytes (PMN). The reported procedure far the synthesis of these compounds is multistep in nature and involves harsh reaction conditions such as Fridel-Crafts acylation and acid/base mediated condensations. A plausible approach will be the one-pot sequential metal-catalyzed cyclization of 2-alkynylphenols followed by the trapping of the intermediate aryl metal species with α,β-unsaturated carbonyl compounds. The second step can be conducted either in an oxidative fashion leading to C3 alkenylation products or under a redox neutral process to access the C3-alkylated derivatives.
WO2013014480, WO2003050102 and WO2007011835 described the use of aroyl benzofuran compounds as anti-inflammatory agents.
In 2011, T. Satoh, et al. reported ruthenium-catalyzed oxidative vinylation of heteroarene carboxylic acids with alkenes via regioselective C—H bond cleavage in org. lett. 2011, 13, 706-708. The method involves the C2 carboxylate directed cross-dehydrogenative coupling of alkyl acrylates and benzo[b]furan-2carboxylate derivatives. The cheap and inexpensive [RuCl2(p-cymene)]2 has been employed as the catalyst and Cu(OAc)2.H2O as the stoichiometric oxidant. The reactions proceeded with complete linear selective alkenylation. The applicability of this ruthenium (II)-mediated cross dehydrogenative couplings has been explored further by several other groups employing a wide range of directing groups on both aryl and heteroaryl rings.
Very recently, a palladium-catalyzed C3 direct arylation of 2-substituted benzo[b]furans with aryl bromides has been reported by Bertounesque and co-workers (J. Org. Chem., 2012, 77 (3), pp 1316-1327).
Shibata and co-workers (J Am Chem Soc. 2012 Oct. 24; 134(42): 17474-7) reported the cationic iridium-catalyzed C2-alkylation of N-substituted indole derivatives using alkenes and acrylates. In case of alkenes, the regioselectivity can be tuned towards linear or branched alkylation by selecting an appropriate N-protecting group.
Vincent Ritleng et al. in Chem. Rev. 2002, 102, 1731-1769 discloses Ru-, Rh-, and Pd-catalyzed C—C bond formation which involves C—H activation and addition on unsaturated substrates, it further describes reactions of furans with acrylates in the presence of the Pd(OAc)2-Cu(OAc)2 catalyst system, in presence of tertbutyl perbenzoate as oxidant.
Ruthenium-catalyzed ortho-C—H bond alkylation of aromatic amides with α,β-unsaturated ketones is disclosed by Guy Rouquet et al Chem. Sci., 2013, 4, 2201-2208, whereas Dr. James w. Walton et al in Angewandte Chemie International Edition 51(49), 12166-12168, 2012 describes ruthenium-Catalyzed ortho-alkylation of phenols with alcohols by dehydrative coupling.
Despite its widespread application in dehydrogenative couplings, surprisingly, the Ru-catalyzed regioselective alkylation with acrylates via C—H activation has not yet been documented. Therefore industrially viable, technically advanced process for regioselective alkylation of benzofuran compounds in suitable catalyst involving C—H activation is desirable to obtain biologically active benzofurane derivatives.